Project Summary/Abstract (Development Core) The Development Core (DC) and the Untargeted Analysis Resource Core (UARC) will collaborate, with the overall aims to increase the range of analytes or biological markers that are detected and identified that reflect environmental exposures. The DC will work with the Big Data Analytics of UARC to prioritize the sourcing of compounds. The DC will optimize extraction procedures for new matrices, in addition to the matrices already analyzed (e.g., urine, serum, plasma, feces, saliva and sweat), and will conduct analyses of biospecimens collected and stored under different conditions to inform best practices for epidemiology studies. They will establish an untargeted method using gas chromatography coupled to an orbitrap mass spectrometer (GC-Q- Exactive) to expand the services offered by the UARC. The DC will also use GC- and liquid chromatography (LC)-Mass spectrometry with Multiple Reaction Monitoring (MRMs) and MSn to develop specific broad spectrum panels for rapid quantitative analysis of analytes that are difficult to detect on the untargeted platforms. The DC will be directed by Dr. Timothy Fennell (MPI, RTI), who has extensive experience with chemical exposure, metabolite identification and toxicity, and exposure biomarker development.